Super‐heating degree responsive control strategy of variable refrigerant flow air conditioning system for energy saving and stable operation
Abstract The control strategy is important for variable refrigerant flow (VRF) air conditioning system to realize energy saving and stable operation. In this work, the super‐heating degree (SHD) responsive control strategy was developed to dynamically adjust the respective SHD target value (ΔTe,tar)...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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Wiley
2023-09-01
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| Series: | Energy Science & Engineering |
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| Online Access: | https://doi.org/10.1002/ese3.1515 |
| _version_ | 1797689193977085952 |
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| author | Qiu Tu Lina Zhang Xiaoyuan Yuan Jianjun Jiang Fangming Ye |
| author_facet | Qiu Tu Lina Zhang Xiaoyuan Yuan Jianjun Jiang Fangming Ye |
| author_sort | Qiu Tu |
| collection | DOAJ |
| description | Abstract The control strategy is important for variable refrigerant flow (VRF) air conditioning system to realize energy saving and stable operation. In this work, the super‐heating degree (SHD) responsive control strategy was developed to dynamically adjust the respective SHD target value (ΔTe,tar) of indoor units so as to adapt to the variable cooling load. The capacity code (Ecode) is introduced into the control model to quantify the reference target value of SHD. To responsively adapt to variable cooling load, the correction target values of SHD based on discharge temperature and deviation of the outlet air temperature are introduced in the SHD model for operation protection of the compressor and the consistency of refrigerant distribution. The enthalpy difference analogy method is developed to estimate the performance of the VRF system including cooling capacity, electric power, and energy efficiency ratio (EER). The performance was tested under the conditions of different ΔTe,tar. Experimental results demonstrate that the ΔTe,tar is an important factor to determine the operation frequency, which affects cooling capacity, power, EER, and operation status of the system. The cooling capacity and electric power at the ΔTe,tar of 9°C was about 55.2% and 63.5% lower than those at the ΔTe,tar of 1°C, and the corresponding EER was improved by 22.6%. To further verify the SHD control strategy, the VRF system was tested by the responsive control model under the condition that Ecode and ΔTe,tar were constantly automatically adjusted and changed with the actual indoor ambient temperature. Experimental results demonstrate that the VRF system can achieve a good and uniform cooling effect and realize energy saving and stable operation according to the responsive super‐heating degree control. |
| first_indexed | 2024-03-12T01:42:23Z |
| format | Article |
| id | doaj.art-6a969089186e4031991a19b5d8747547 |
| institution | Directory Open Access Journal |
| issn | 2050-0505 |
| language | English |
| last_indexed | 2024-03-12T01:42:23Z |
| publishDate | 2023-09-01 |
| publisher | Wiley |
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| series | Energy Science & Engineering |
| spelling | doaj.art-6a969089186e4031991a19b5d87475472023-09-10T08:27:34ZengWileyEnergy Science & Engineering2050-05052023-09-011193215323110.1002/ese3.1515Super‐heating degree responsive control strategy of variable refrigerant flow air conditioning system for energy saving and stable operationQiu Tu0Lina Zhang1Xiaoyuan Yuan2Jianjun Jiang3Fangming Ye4Department of Building Environment and Energy Application Ningbo University of Technology Ningbo City Zhejiang Province ChinaDepartment of Building Environment and Energy Application Ningbo University of Technology Ningbo City Zhejiang Province ChinaZhejiang Zhong Guang Electric Appliance Co., Ltd Lishui City Zhejiang Province ChinaZhejiang Zhong Guang Electric Appliance Co., Ltd Lishui City Zhejiang Province ChinaZhejiang Zhong Guang Electric Appliance Co., Ltd Lishui City Zhejiang Province ChinaAbstract The control strategy is important for variable refrigerant flow (VRF) air conditioning system to realize energy saving and stable operation. In this work, the super‐heating degree (SHD) responsive control strategy was developed to dynamically adjust the respective SHD target value (ΔTe,tar) of indoor units so as to adapt to the variable cooling load. The capacity code (Ecode) is introduced into the control model to quantify the reference target value of SHD. To responsively adapt to variable cooling load, the correction target values of SHD based on discharge temperature and deviation of the outlet air temperature are introduced in the SHD model for operation protection of the compressor and the consistency of refrigerant distribution. The enthalpy difference analogy method is developed to estimate the performance of the VRF system including cooling capacity, electric power, and energy efficiency ratio (EER). The performance was tested under the conditions of different ΔTe,tar. Experimental results demonstrate that the ΔTe,tar is an important factor to determine the operation frequency, which affects cooling capacity, power, EER, and operation status of the system. The cooling capacity and electric power at the ΔTe,tar of 9°C was about 55.2% and 63.5% lower than those at the ΔTe,tar of 1°C, and the corresponding EER was improved by 22.6%. To further verify the SHD control strategy, the VRF system was tested by the responsive control model under the condition that Ecode and ΔTe,tar were constantly automatically adjusted and changed with the actual indoor ambient temperature. Experimental results demonstrate that the VRF system can achieve a good and uniform cooling effect and realize energy saving and stable operation according to the responsive super‐heating degree control.https://doi.org/10.1002/ese3.1515compressor output capacityenergy efficiency ratiosuper‐heating degreesuper‐heating degree responsive controlvariable refrigerant flow |
| spellingShingle | Qiu Tu Lina Zhang Xiaoyuan Yuan Jianjun Jiang Fangming Ye Super‐heating degree responsive control strategy of variable refrigerant flow air conditioning system for energy saving and stable operation Energy Science & Engineering compressor output capacity energy efficiency ratio super‐heating degree super‐heating degree responsive control variable refrigerant flow |
| title | Super‐heating degree responsive control strategy of variable refrigerant flow air conditioning system for energy saving and stable operation |
| title_full | Super‐heating degree responsive control strategy of variable refrigerant flow air conditioning system for energy saving and stable operation |
| title_fullStr | Super‐heating degree responsive control strategy of variable refrigerant flow air conditioning system for energy saving and stable operation |
| title_full_unstemmed | Super‐heating degree responsive control strategy of variable refrigerant flow air conditioning system for energy saving and stable operation |
| title_short | Super‐heating degree responsive control strategy of variable refrigerant flow air conditioning system for energy saving and stable operation |
| title_sort | super heating degree responsive control strategy of variable refrigerant flow air conditioning system for energy saving and stable operation |
| topic | compressor output capacity energy efficiency ratio super‐heating degree super‐heating degree responsive control variable refrigerant flow |
| url | https://doi.org/10.1002/ese3.1515 |
| work_keys_str_mv | AT qiutu superheatingdegreeresponsivecontrolstrategyofvariablerefrigerantflowairconditioningsystemforenergysavingandstableoperation AT linazhang superheatingdegreeresponsivecontrolstrategyofvariablerefrigerantflowairconditioningsystemforenergysavingandstableoperation AT xiaoyuanyuan superheatingdegreeresponsivecontrolstrategyofvariablerefrigerantflowairconditioningsystemforenergysavingandstableoperation AT jianjunjiang superheatingdegreeresponsivecontrolstrategyofvariablerefrigerantflowairconditioningsystemforenergysavingandstableoperation AT fangmingye superheatingdegreeresponsivecontrolstrategyofvariablerefrigerantflowairconditioningsystemforenergysavingandstableoperation |